1. Field of the Invention
The present invention relates to a system and method of avoiding vehicle collisions in intersections. More specifically, the present invention relates to detecting the presence of a threat vehicle approaching the same intersection as the subject vehicle.
2. Discussion of Background Information
Roadway intersections are areas of potential conflict that increase risk exposure for vehicles attempting to pass through these locations. The varying nature of intersection configurations and the number of vehicles approaching and negotiating through these sites result in a broad range of crash scenarios. Preliminary estimates by the National Highway Traffic Safety Administration (NHTSA) indicate that crossing-path crashes occurring at intersections represent approximately 26 percent of all police-reported crashes each year, approximately 1.7 million crashes per year. Consideration of non-police-reported crashes of this type raises the total number of crossing-path crashes to approximately 3.7 million per year. These crashes can be classified into four scenarios (from the perspective of a vehicle that initiates the crash events).
FIG. 1 shows the first scenario. A subject vehicle 100 is not required to stop, there is no violation of a traffic control device, and subject vehicle 100 is slowing or stopped in a traffic lane. Subject vehicle 100 may be required to yield but not stop, such that there is no violation of the control device. A majority of these cases involve subject vehicle 100 approaching a traffic signal with a displayed green phase, whereas the remaining cases involve intersections for which the direction of travel of subject vehicle 100 is not controlled by a traffic control device. The crash occurs when subject vehicle 100 attempts a left turn across the path of an oncoming threat vehicle (POV) 102. Typically, subject vehicle 100 is either slowing, or at a stop in the traffic lane.
The second scenario is shown in FIG. 2. In this case, subject vehicle 100 is required to stop by a traffic control device, stops in accordance with the control device, and proceeds into the intersection. Almost all the cases in this category are intersections controlled by stop signs along the roadway being traveled by subject vehicle 100. No traffic control is present on the roadway being traveled by other vehicle 102. The crash occurs when subject vehicle 100 attempts to traverse the intersection or to perform a left turn onto the roadway being traveled by threat vehicle 102.
FIG. 3 shows the third scenario. Although subject vehicle 100 is required to stop consistent with a traffic control device, subject vehicle 100 enters the intersection without stopping (in violation of the traffic control device). In the majority of these cases, subject vehicle 100 is proceeding straight (i.e., not turning).
The fourth scenario is shown in FIG. 4. In this case, subject vehicle 100 approaches an intersection controlled by a signal with a displayed red phase. Subject vehicle 100 stops, and then proceeds into the intersection before the signal phases to green.
Various systems, such as the VORAD collision avoidance system, and the Mercedes-Benz Stability Enhancement System, illustrate the potential to detect collision situations, and to control the stability of the vehicle during a collision avoidance maneuver. Application of these and other state-of-the-art technologies is part of a program to revolutionize transportation safety. This program, broadly titled Intelligent Transportation Systems (ITS), seeks to integrate sensors and processing equipment into automobiles to increase their safety and utility. However, these systems primarily apply to rear end and lane change collisions, and fail to provide comprehensive prevention of intersection-based collisions.
The present invention provides a method and system for avoiding intersection-based collisions between a subject vehicle and other vehicles in a manner that overcomes the drawbacks of the prior art.
The present invention includes a radar system that tracks other vehicles near an intersection. A collision avoidance system compares the predicted location of these other vehicles with the predicted location of the subject vehicle to identify potential overlap within the intersection. Appropriate warnings are issued in response to a detected overlap.
The preferred embodiment of the present invention directs the scanning angle of its left and right side radar system relatives to left and right control points on a non-parallel road. As the subject vehicle moves toward the intersection, each control point is preferably being continually recalculated to move away from the subject vehicle along the intersection to maintain a constant distance from the subject vehicle. The antenna controller points the antennas based on the position of the control point and rotates the antennas to scan in small sectors relative to the control point.
According to an embodiment of the invention, a method for a subject vehicle to avoid collisions is provided. At least one lane feeding into an intersection is scanned. The presence of a threat vehicle in the at least one lane is detected. Whether the subject vehicle and the threat vehicle will occupy the intersection at the same time is predicted. A warning is issued in response to the predicting.
According to another embodiment of the invention, a method for a subject vehicle to avoid collisions is provided. There is a separate scanning of left, right, and forward sectors of the subject vehicle in response to the subject vehicle coming within a predetermined distance of an intersection. The presence of a threat vehicle in the at least one lane is detected. Whether the subject vehicle and the threat vehicle will occupy the intersection at the same time is predicted. A warning is issued in response to the predicting.
According to yet another embodiment of the invention, a method of controlling a radar antenna mounted on a moving vehicle is provided. The radar antenna is oscillated about a predetermined angle relative to a control point, the control point representing a position in a lane feeding into an intersection. The control point is moved away from the intersection as the subject vehicle approaches the intersection.
According to still yet another embodiment of the invention, a method for preventing a subject vehicle from accidents in intersections is provided. A map is stored in a database, the map including at least one intersection with a traffic control device. Coordinate data reflecting a position of the subject vehicle is received. Whether the subject vehicle will enter an intersection of the at least one intersection in violation of an associated traffic control device is determined. A warning is issued to a driver of the subject vehicle in response to a determination that the subject vehicle will enter an intersection of the at least one intersection in violation of an associated traffic control device. An area around the intersection is scanned. Any threat vehicles in the scanned area are identified. Whether the subject vehicle and the threat vehicle will occupy the intersection at the same time is predicted. A warning is issued to the driver of the subject vehicle in response to a prediction that the subject vehicle and the threat vehicle will occupy the intersection at the same time. Whether prevailing conditions indicate a low probability of a collision in the intersection is determined. The warning to a driver of the subject vehicle is disabled in response to a prediction when the prevailing conditions indicate a low probability of a collision in the intersection.
According to yet another embodiment of the invention, a collision prevention device mounted on a subject vehicle is provided. Left, right and center radar antennas are mounted on the vehicle. A controller is programmed to oscillate the left and right radar antennas about a predetermined angle relative to left and right control points respectively, the control points representing positions in left and right lanes feeding into an intersection. The controller is also programmed to move the left and right control points away from the intersection as the subject vehicle approaches the intersection.
According to still yet another embodiment of the invention, a collision prevention device is provided. Left, right and center radar antennas are provided. A map database is also provided, where a map in the database including an intersection. A tracker is capable of distinguishing a threat vehicle approaching the intersection from other objects detected by the left, right, and center radar antennas. A controller is capable of determining whether the subject vehicle and the threat vehicle will occupy an intersection at the same time. The controller is programmed to issue a warning signal in response to whether the subject vehicle and the threat vehicle will occupy an intersection at the same time and when the prevailing conditions do not indicate a low probability of a collision in the intersection.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawings.